Lining for pulp-digesters



2 Sheets-Sheet 1.

(No Model.)

f s. R. WAGG.

LINING FOR PULP DIGESTERS.

No. 390,727. Patented Oct. 9, 1888.

l@ fr? Solomon,

2 Sheets-Sheet 2.

Patented Oct. 9, 1888.

- (No Model.)

S. R. WAGG.

LINING Foe PULP DIGESTERS.

N. PETERS. Pnewunwgmpher. washingum n. c.

. with varying degrees of success.

NiTnn STATES PATENT intera SOLOMON n. wade, OF NEENAH, WISCONSIN.

LINING FOR PULP-DIGESTERS.

SPECIFICATION forming part of Letters Patent No. 390,727, dated October9, 1888.

(No model.)

.To @ZZ whom t may concern: l

Bc it known that I, SOLOMON R. Whoo, a citizen of the United States ofAmerica, residing at Neenah, in the county of Winnebago and State ofWisconsin, have invented certain new and useful Improvements in Liningfor Boilers and Pulp-Digesters or other Vessels Exposed to the Action ofAcids, of which the following is a specification.

Heretofore boilers used in the treatment of wood fiber by the bisulphiteprocess have been lined with lead in sheets to protect the shell fromcorrosion and the contents *from stain; but a defect in all boilers thuslined has been that the steel or iron shell and the lead lining do notexpand and contract equally, and that after short use the lining beginsto creep and crack and admits the acid to contact with they shell. ToObviate the effects of this unequal expansion and contraction of thelead and prevent cracks and consequent leakage and injury to the shelland to the contents of the boiler or material under treatment, numerousdevices have been placed before the publie Some manufacturers havesupplied boilers with an interior lining made in practically onehomogeneous piece by soldering the edges of one or more sheets together.Others have divided the lining into sections and covered the joints withstrips. Others have inclosed finely-perforated sheet-iron in a casing oflead, making plates or broad sheets to be applied as lining. Stillothers have covered woven-wire cloth with lead. None of theseconstructions, however', have been entirely free from objections or havebeen entirely satisfactory in use.

In my improvement I propose, first, to apply the lead lining in smallsections or tiles, each of these sections in itself containing severalindependent anchors or local resistances to the expansion andcontraction, and practically shutting off the areas so confined frombeing affected by other areas and more nearly harmonizing them with theexpansion and contraction of the shell; second, I partition the interiorof the boiler-Shell,by means of ribs or stays of metal bolted to theinterior wall of said shell, into a number of practically equal shallowcompartments, each of which will be independently lined by tiles coatedwith lead or other acid resistant, so that any leak or defeet may bereadily remedied within the com-l partment in which it is found withoutdisturbing the tiles in the other compartment; third, I employ apeculiar bolt and nut for securing the tiles independently to theboiler-shell, having a groove cut in said nut and bolt, so that leak ageis at once conducted to the outside and the locality of leakageindicated, for which purpose the exterior may have designatinglinescorresponding with those of the interior partitions, and, if desired, befurnished with a number reproduced on the interior; fourth, I propose toelectroplate the interior of the iron or steel boiler-shell withphosphor-bronze or other equivalent composition before applying the leador acid-resistant lining to more perfectly guard against damage byleakage; fifth, I have found that an alloy hereinafter stated expandsand contracts in nearly equal Ineasure with the iron and steel shell ofthe boiler while resisting the destructive effects of acids as well asor even better than lead, and such I propose to use and to claim herein.

Other features of my invention will appear from the ensuing description.

In the drawings, Figure I is a side elevation of a boiler embodying myinvention, the shell being partly broken away to expose the internalconstruction; Fig. 2, a transverse section therethrough; Fig. 3, anenlarged detail of a portion of the inside of the boiler, showing at theright hand a lining-tile with lead covering in place and at the left theadjacent tile uncovered; Fig. 4, a longitudinal section on thecorrespondingly-numbered line in the preceding figure; Fig. 5, a bottomplan view of one of my improved tiles, showing the channels or ducts toconduct air or leakage to the boltholes through the boiler-shell; Figs.6 and 7, respectively, enlarged details in perspective of afastening-bolt and its nut for .securing the lining to the boiler-shell,and Figs. 8 and 9 enlarged details of alternative forms of washers whichmay be used with said nut.

A represents a boiler-shell, of iron, steel, or other suitable material,of any approved outline, depending in some measure upon whether it is tobe stationary or rotary. To the interior walls of this shell are boltedlongitudinal bars or stays B and transverse bars or stays B', of metal,dividing said walls off into a number of shallow and independent com-IOO partments or cells, C, rectangular in outline. These compartmentsmay be indicated upon the exterior of the boiler by lines or marks C,corresponding with the longitudinal and transverse stays which definetheir limits, and by numerals l, 2, Snc., to be reproduced on theinterior, so that any compartment may be immediately located from theoutside. Each compartment is to be filled with acid-resistant tiles, aswill presently appear, and one or more tiles, or every tile, willadvisably have communications with the exterior surface of the shellthat will permit leaks within the compartment to be traced on theoutside and immediately located by the designating-number of thecompartment. t

So far as the division ofthe shell into inde pendent internalcompartments is concerned, any suitable form of acid-resistant tile orlining may be employed without departing from my invention; but the tilewhich I have devised and prefer to use is constructed as follows: I forma frame, D, of hard metal, preferably of angle'iron, ofthe shape desiredfor t-he outside margin or edge of the tile or section, eitherrectangular, as shown in the drawings, or a polygon, that will allow thetiles to be laid and matched edge to edge-for instance, a hexagon oroctagonal and square tiles may be combined in the same structure. Theupright ange of this frame will be recessed, grooved, or undercut aroundits exteriorside, as described in an application heretofore iiled by me,in order to admit between it and the adjacent tile when in position asort of dovetail seam or tamping of acid-resistant material, and thestays which define the compartments to be filled by these tilesorseetions may also be undercut along their sides, that with the tilescoming adjacent to them such a seam or tamping may be formed.

Within the angleiron frame llay a series of strongiron, steel, or othermetal rings, E, ofsuccessively diminishing diameter. These rings will becomparatively thin and shallow and ordinarily will not rise to theheight of the angleiron frame which incloses them. A large ring is lirsttaken, having such diameter as to just lie within the frame withouttouching its walls, giving a minimum clearance all around of,say,onehalf an inch to a full inch. The next ring is laid within thefirst with a clearance all around from said first ring of about thesame, care being taken that their walls shall be equidistant at everypoint. The next smaller ringislaid within the seeond,with likeclearance, and so on until the full series of rings are interposed, thelast or central ring preferably being not over three inches in diameter.Vhen the inelosing-frame is rectangular in outline, the outer ring willleave large triangular spaces at the corners, which will be iilled withsmaller series, E', of diminishing rings; but when it is hexagonal oroctagonal the outer ring will practically correspond with be immaterial.

rings having been previously prepared with a coating of any suitablesolder to cause the lead to adhere firmly when poured upon them in itsmolten state, the next proceeding after they are thus assembled is topour upon them, while they rest uponasuitable table to ent oill escapeof the fluid metal, molten lead or equivalent acid'resistant alloy,lforming the whole into a single section or tile, and protecting all theexposed iron or steel parts with an unbroken covering.

The tile-table,when square, should preferably have at each corner abolt-hole with a bolt, F, set therein before the reception ofthe leadcovering, such bolt to be of sufficient length to reach to the outsideof the boiler-shell. A4 small' groove or channel, f, is made from theedge ot' the angle-iron to the bolt-hole, and such groove may beextended over the under side ofthe plate or tile and may branch therebeneath. The shank or spindle of the boit is channeled, grooved, ortinted longitudinally, as at f', to afford one or more ducts leadingfrom the head to the exterior wall of the boilershell and to or adjacentto its end, which is screw-threaded, so that alter being passed throughthe shell it may receive a nut., 1i', whereby the tile can be firmlyclamped to said shell. Il" this nntalone is used it will have an annularundercut groove, f2, or be countersunk on its inner face, so as toconnect with the groove or flutes in the spindle of the bolt, and willhave ductsf" leading from this countersink or groove to its exterior;but prefera bly a washer, F2, is employed, either grooved similarly tothe inner face ofthe nut and having ducts or else struck up with threeor more feet, f3, to lift it somewhat from the boilershell. Thus anyleakage which finds its way beneath the tile and attacks the inner wallof the boiler will eventually enter the ducts or channels on the underside of the tile and be conducted to the bolt at one or the othercorner, then pass along its grooved spindle to the exterior wall oftheshell, and eventually escape from beneath the washer or nut, makingits presence at once known, when it will be 1ocated according to thecompartment where it makes its appearance. Another purpose of thisgrooving and iluting is that when placing the tile or section inposition any air confined underneath it may escape to the exterior asthe bolts are tightened. Such air, if permitted to remain confinedbeneath the section, would expand as soon as the boiler became heated inuse, and would in the end, by repeated expansion and contraction, causebubbles or bulging in the tile and cracking in the plate.

In case it should be desired to leave out the fastening-bolts whilecasting the lead lining about the angleiron frame and rings, theboltholes can be filled with clay and the lining cast over them, andwhen cool, or when ready to place in position, the lining can bepartially out with a suitable tool and turned up, leaving the bolt-holeclear. The bolt can then be in sertcd and the lining tu rned to itsoriginal posi- IOO IIO

tion and fused acidtight; or the bolt-hole can be elongated and thebolt-head formed. as a sort of T, so that this hole being stopped upwith clay while the lining is being poured can be cleared out withoutpuncturing the lining after it becomes cool, the bolt-head t-hen beinginserted and given a quarter-turn, thus contining it. The lining may behammered down upon it to prevent its escaping by a reverse movement. Aseries of these sections prepared with rings and acid-proof linings willbe laid in each compartment of the internal wall of the shell, thediameter of the tiles or sections being so proportioned to the size ofthe compartments that a given number may perfectly iill a compartment.The seams between these tiles and between the tiles and stay-rods orpartition-bars will be filled and tamped with lead, which will also becarried over the stay-rods, so that no destruct-ible material may beexposed to the action of the acids within the boiler.

As an additional precaution against buck ling or bulging or warping, Ipropose to employ a hard-metal radial-armed frame or spider, G, its armg extending close up to the edge of the angleiron frame, and having acommon center or hub, g', corresponding with the axis of the centralring in the tile. This will be placed in position upon the rings andtheir lead covering and secured by a bolt, g2, passing through the axisof the central ring and the exterior ofthe boiler-shell, and, ifdesired, by other bolts passing through the ends of the radial arms, asshown. Then the frame or spider itself, including the heads of itssecuring-bolts, will be covered with lead or other acid resist-ant,unless this has previously been done. A lead washer may be placedbeneath the spider at the point where its bolt passes through the leadlining of the tile, so that when the bolt is tightened up the washer maybe jammed down upon thc lining and make a tight joint. The spider holdsall the rings dat down against the boiler-wall, thereby assist ing tokeep said rings in position, so they can work in harmony to counteractthe expansion of the lead or alloy and establish a uniform rate ofexpansion for the lining and boilen Walls as near as may be. Instead ofthis spider frame, however, I may employ one or more straight bars laidover the rings parallel to each other and bolted at their ends orcenters to the boiler shell; but as ordinarily a single bolt at thecenterof the tile alone will be suffr cient when the radial -arm spideris used, I prefer this, as it diminishes the chances of leakage.

Over all of the seams, after the filling and calking are completed, Iplace a ribbon, II, of lead or alloy, and by solder or any otherconvenient method unite the same to each of the conjoining tiles at theupper edges or outside oftheir leadcovered angleiron frames, making theunion acid-tight by using blow-pipe or solder-iron, thereby causing theseam to form a compound joint and preventing against possible leakage.When desirable, the filling can be fused at its edges with the coveringof the angle-iron walls before placi ng the ribbon over such filledseam.

As an additional security against acid attacking the boiler-shell, as itmay sometimes do by leaking through the tiles or seams, or

through the lead or otherlining in case no tiles are used, I propose toclean the boiler-walls and prepare them in a suitable manner forreceiving a cover of any acidresistant metal or material by electroplating or deposition applied in the usual way, or by such means andappliances as are in use and best suited forthe purpose. Suchelectroplate deposition can be made on sheets or sections of the shellbefore making up or upon the shell after construction. The material Ipropose to employ for this electro deposition is phosphor-bronze ordeoxidized copper or alloy. This, as above intimated, should be appliedto the walls before the lead lining` or acid-resisting tiles are placedthereon. Thus' 'far I have described a lining of lead or acid-resistingsurface of lead alone, although it has been suggested that any y otheracid-resistant metal or alloy might be utilized. Lead, when heated,expands much more than iron or steel, which are the usual materials forboiler-shells of this nature, (in this art,) and when it cools it doesnot return quite to its original form or size like iron or steel, butcach time it is heated it stretches out or creeps, thickening u p in oneplace, thinning down in another, and buckles up and soon cracks through,admitting the corrosive liquor to contact with the shell, which, beingvulnerable to acid, is speedily destroyed, while conversely the pulp inthe process of being cooked is spoiled by the result-ing metallic salts.I have ascertained that an alloy composed of lead, bismuth, andantimony, which may be so regulated as to expand and contract inpractically the same degree as or in harmony with the expansion andcontraction of the metal boiler-shell, whether that be iron, steel, orother metal, by varying the propor tions of the bismuthor the antimonyto the lead,will at the same time resist effectively the, corrosiveaction of the powerful acids employed in the bisul-phite process.Bismuth and anti-l mony are both what is known as volatile, and must bemelted with care and not leftlongexposed to the heat, or the natureofthe eX- pected expansion will be affected thereby. It will thereforebe advisable to melt the bismuth and antimony in inclosed tight vessels,and to pour them, when tiuid, into the melted lead and stir quicklytogether therewith.

A precise and arbitrary rule of weights and proportions is notpracticable, and as results will be only closely approximate I can onlygive au approximate statement of such proportions, bearing in mind thatif melted in an open vessel the fluid metals will lose slightly morethan in a covered Vessel, and in such case a little more must be used toget the samelresult.

IOG

IIO

` that is a superior acid resistant.

In forming an alloy for the lining, if iron, I combine the stated metalsin about the following proportions, towit: Of leadI take eightyfourparts, of antimony twelve parts, and of bismuth fou r parts, thusobtaining an alloy that has but a very slight expansion over iron and Bythe addition of slightly more antimony and bismuth the alloy can be madeto expand less. Should a very tough alloy be required, I propose to adda small quantity of phosphor-bronze or deoxidized copper. This willinterfere with the unity of expansion and contraction, if much is used,and to bring the expansion and contraction down to the point aimed atthere must be an increase in the amount of antimony and bismuthaccording to the quantityofphosphor-bronze used. The proportions, forinstance, may then be stated as follows for lining an iron shell, towit:lead, seventy-tive per cent.; antimony, fourteen per cent.; bismuth,iive per cent., and phosphonbronze six per cent. I have used copper inplace of phosphor-bronze with fair results, but not as good, and givethe bronze preference.

I do not intend to limit myself lo the employment of separate andindependent rings in constructing my improved tile, nor to the materialof which they are made, provided that material expands and contracts iucorrelation with the expansion and contraction of the boiler-shell, butmay form these rings (and their frame as well) by sinking orindentationin a homogeneous plate 0r by raising or strilc ing up the same from thesurface, and upon said plate or surface cast the acid-resistant coatingor lining, or place it thereon by other or equivalent means; nor do Iconfine myself to the precise means for fastening said tiles, nor to theprecise shape of the divisions or compartments on the inner wall of theboilershell, since these can be materially varied without departing fromthe principle of my invention.

I claim- 1. A boiler-shell having its interior walls divided intoshallow compartments by ribs or stays, combined with independentacid-resistant lining in each of said compartments and acid-resistantcovering to said stays.

2. A boiler-shell havingits interior wallsdivided by ribs or stays intoshallow compartments independently iilled with acid-resistant lining andits exterior walls marked to correspend with said compartments.

3. Aboilereshell having its interior walls divided into shallowcompartments by ribs or stays bolted to said Walls,combined withacidresistant lining for said ribs or stays and with acidresistant tileslining the walls within said independent compartments.

4. rIhe tile herein described, consisting of a border-frame of hardmetal, a series of diminishing rings of steel or iron, andanacid-resist-ant covering incorporating said rings and the borderframe.

5. The tile herein described, consisting of a frame of angle-iron, aseries of diminishing rings of steel or iron, and an acid-resistantcovering incorporating said rings and the angle-iron.

6. The tile herein described, consisting ofa frame of angle'iron, aseries of independent rings of steel or iron diminishing in size and setwithin said frame, and a lead covering incorporating the exposed facesof the frame and rings.

7. The combinatiomwilh tiles for the lining of boilers grooved at theinner side, of fasteningbolts having their spindles grooved to connectwith the grooves of the tiles and secured by channeled nuts on theoutside ofthe boiler.

8. The combination,with atile composed of an angleAirou fran1c,a seriesof diminishing rings placed therein, and an acid resistant coveringincorporating said ring and frame,ofan acid-resistant covered spidercomposed of radial bars or equivalents, and having a central boltpassing centrally through the tile and covering the rings, and itselfcovered with acid resistant.

9. The combination, substantially as herein` before set forth, with theboiler-shell, of an electroplating of phosphor-bronze or equivalentmaterial covering its internal walls and an acid resistant liningsecured over said plating.

10. The combination, substantially as here inbefore set forth, with theshell of a paperpulp boiler or digester, of an acid-resistant liningcomposed of antimony, bismuth, and lead, in about the proportions setforth, and with or without phosphorbronzc or equivalent.

S( lLOM'( )N It. W A GG.

\V it ncsscs:

H. Gv. FRJMQMAN, ll. KUcHUnsoNn.

ICO

